ACR

The ACR is first used in the mission Cliffhanger, with a Red Dot Sight, Silencer and Heartbeat Sensor attached. Its damage is equivalent to the M4 Carbine but is much more accurate, having the least recoil of any of the fully automatic weapons. Because of the ACR's high rate of fire and low recoil, it is more usable without Stopping Power than most guns. In multiplayer, the weapon is unlocked at Level 48.

The ACR has less recoil than and fires faster than the M4 while doing the same damage, meaning that the M4 becomes obsolete upon unlocking the ACR. Many people are unaware of this fact, and continue using the M4, even though the ACR is statiscally better.

Most attachments work well with this weapon. All of the sights including the Thermal Scope can be used with it, due to its very low recoil.